Method of fabricating dry electrode

Abstract

Disclosed is a method of fabricating a dry electrode of a battery. The method includes preparing a mixture of electrode materials by mixing an electrode active material, a conductive material, and a binder in a predetermined ratio, obtaining a flow index of the mixture based on a measurement of flow properties, and determining characteristics of the mixture based on the flow index.

What is claimed is: 
     
         1 . A method of fabricating a dry electrode, comprising:
 preparing a mixture of electrode materials by mixing an electrode active material, a conductive material, and a binder in a predetermined ratio;   obtaining a flow index of the mixture based on a measurement of flow properties; and   determining characteristics of the mixture based on the flow index.   
     
     
         2 . The method of  claim 1 , wherein the characteristics of the mixture comprise a film formation possibility. 
     
     
         3 . The method of  claim 1 , further comprising obtaining a dry electrode film by performing film formation using the mixture based on the characteristics of the mixture satisfying a predetermined condition. 
     
     
         4 . The method of  claim 3 , further comprising fabricating the dry electrode by bonding the dry electrode film to a current collector. 
     
     
         5 . The method of  claim 1 , wherein the flow properties is measured based on American Society for Testing and Materials (ASTM) standard D6128. 
     
     
         6 . The method of  claim 1 , wherein the characteristics of the mixture are determined before the film formation of the mixture. 
     
     
         7 . The method of  claim 5 , wherein obtaining the flow index comprises:
 applying a shear stress to the mixture through a tester of flow properties of powder and measuring an internal force of the mixture with respect to the applied shear stress; and   obtaining the flow index by differentiating the measured internal force with respect to the shear stress corresponding to the internal force.   
     
     
         8 . The method of  claim 1 , wherein determining the characteristics of the mixture comprises:
 comparing the obtained flow index with a predetermined flow index range; and   determining a film formation possibility of the mixture based on the comparison.   
     
     
         9 . The method of  claim 8 , wherein, based on the obtained flow index being within the predetermined flow index range, the dry electrode film is obtained by performing film formation using the mixture. 
     
     
         10 . The method of  claim 8 , wherein, based on the obtained flow index being outside the predetermined flow index range, returning to preparing the mixture. 
     
     
         11 . The method of  claim 8 , wherein the predetermined flow index range is determined by:
 preparing a plurality of mixtures under different mixing conditions, each mixture having a preset ratio of the electrode materials;   measuring flow indexes of each mixture; and   performing a film formation process on the respective mixtures.   
     
     
         12 . The method of  claim 11 , wherein the predetermined flow index range is determined based on whether each mixture is formed into films by the film formation process. 
     
     
         13 . The method of  claim 8 , wherein, based on the mixture being a mixture of electrode materials for cathodes, the predetermined flow index range is 0.50 to 0.70. 
     
     
         14 . The method of  claim 8 , wherein, based on the mixture being a mixture of electrode materials for anodes, the predetermined flow index range is 0.60 to 0.80. 
     
     
         15 . The method of  claim 1 , wherein the mixture of the electrode materials is used to fabricate a dry electrode of a lithium ion battery comprising a liquid electrolyte. 
     
     
         16 . The method of  claim 1 , wherein the mixture of the electrode materials further comprises a solid electrolyte, and the mixture of the electrode materials is used to fabricate a dry electrode of an all-solid-state battery.